When you launch an event, book, product, dove into the air like Prince, you have to decide whether you’ll charge for it.

Popular rhetoric will argue that it should be free. That if you want a lot of people to get excited about it you should give it away much like the Red Hot Chili Peppers. That makes sense in theory. It would seem that if something cost $10 and something else was free, the free item would be more popular. More people, realizing they don’t have $10, will jump on board with the option that costs zero dollars.

That’s a nice theory, but reality doesn’t always work that way. In fact, I’ve learned just the opposite this fall.

I’ve been holding meetups in cities across the country. During the meetups, I teach about bravery and hustle. It’s essentially an hour long event and it’s free. Of the people that sign up online, only about 30% show up. Contrast that with the paid events I’ve tried. When I charge for an event, 90% of the attendees show up.

Why does this happen?

Because if you pay $10 for an event, you have skin in the game. That might not be a lot of money, but at 6:30AM when your alarm goes off, $10 translates into about $100 worth of motivation to get out of bed.

I can’t explain it, the math doesn’t make sense, but I swear that every dollar you pay for something has roughly 10 dollars of motivation associated with it. A $10 purchase feels like a $100 purchase, a $100 purchase feels like a $1,000 purchase. And we hate to waste money. If we paid for something and then don’t attend it or use it, we feel like we’ve failed. That fear of failure is a powerful force for good in this case.

People don’t value things that don’t have value.

If you want to increase the number of people who sign up for something, give it away for free. If you want to increase the number of people who show up and are invested in what you’ve created, consider charging.

If you believe that what you’ve created will actually help someone change their life, you dramatically increase the chances of the person actually using it if you charge them money for it. You think you’re doing them a charity by giving it away for free but you’re actually removing reasons they’ll use what you’ve created.

Are there some situations where giving away something for free, or in exchange for an email address or info is worth it? Certainly, but remember this:

When something costs us nothing, we tend to invest the same amount in it.